Harmless · Popular pet · Native to southern California

Coastal rosy boa

Lichanura orcutti

Also called rosy boa
Data updated November 2026

Coastal rosy boa resting on granite rock, showing three rust-brown stripes on a bluish-gray body
Fig. 1 — Adult on granite with three rust-brown stripes on a bluish-gray body.
Close view of a rosy boa head with small eyes, vertical pupils and smooth shiny scales
Fig. 2 — Cat-like vertical pupils and a head barely wider than the neck.

At a glance

A small, heavy-bodied, slow-moving boa of rocky hills, scrub and desert canyons in southern California. It hunts mostly at night, gives birth to live young, and is one of the most popular native snakes in the pet trade.

01

Identification

The coastal rosy boa is a stout, smooth-scaled snake with cat-like vertical pupils and a long head barely wider than its neck. Most have three lengthwise stripes, brown, gray, rust or orange, on a beige, slate-blue, gray or rosy body, though some are nearly uniform gray, pink or brown. The belly is light cream to gray with darker flecks. Males have a small spur on each side of the vent.

  1. 01Three stripes. One down the back and one on each side, sometimes faint or blurry.
  2. 02Thick, smooth body. Glossy scales, a blunt tail and a narrow head with small eyes.
  3. 03Slow and gentle. One of the slowest snakes, moving at about 1 mile per hour, and it very rarely bites.

Commonly confused with

For decades all rosy boas were treated as one species, Lichanura trivirgata, with coastal, desert and Mexican subspecies. A 2008 mitochondrial DNA study of 131 rosy boas found three main lineages that did not line up with those subspecies: one mainly in California and one mainly in Arizona, largely separated by the Colorado River, and a third scattered along the Baja California peninsula, south-central Arizona and coastal Sonora. Many checklists now call the California and Arizona snakes Lichanura orcutti and keep the name Lichanura trivirgata, the three-lined boa, for the third group; some herpetologists still use the older subspecies. The two look very similar, so where the snake comes from is the practical guide.

02

Size

01 ft2 ft3 ft4 ft Typical adult · about 30 in (76 cm)

Adults range from about 17 to 44 inches (43–112 cm), and most stay under about 3 feet. Adult size varies with locality. Newborns are roughly a foot long.

03

Range & habitat

Rocky chaparral hillside in southern California with boulders and coastal sage scrub
Fig. 3 — Rocky chaparral, scrub and boulder-strewn foothills.

Coastal rosy boas live in southern California, from coastal sage scrub and chaparral hills inland to rocky desert foothills and canyons. Rosy boas as a group range from sea level to about 4,500 feet (1,400 m) across southern California, southwestern Arizona and northwestern Mexico. They favor rocky ground with crevices, usually near some source of water, and spend most of their time hidden under rocks, in crevices or in rodent burrows, which shelter them from heat, cold and predators.

04

Diet & predators

Rosy boas hunt mostly at night and kill prey by constriction. Small mammals such as mice make up much of the diet, along with birds, lizards and amphibians.

Feeds on

  • Mice and other small rodents
  • Small birds and nestlings
  • Lizards
  • Amphibians

Preyed on by

Deer mouse on rocky ground at night
Prey — mice.
Red-tailed hawk perched on a dead branch
Predator — hawks.

05

Behavior & seasons

Rosy boas are terrestrial and mostly nocturnal, spending the day tucked into rock crevices or rodent burrows. They are among the slowest snakes, moving at about 1 mile per hour, and rely on staying hidden rather than fleeing.

Because they cannot make their own body heat, they shelter through the hottest and coldest weather. In cold winters they enter brumation, a dormant state similar to hibernation, and become active again in spring, when mating takes place.

06

Reproduction

Rosy boas give birth to live young rather than laying eggs. Mating happens in spring; during courtship the male strokes the female with his small vent spurs. Females give birth in late fall to as many as about 12 young, each roughly a foot long, which are independent from birth.

07

Conservation

The species is assessed as Least Concern and is not federally listed. Much of its coastal range overlaps the fast-growing cities of southern California, so habitat loss and road deaths are local pressures.

Most rosy boas in the pet trade today are captive-bred, often sold under locality names that reflect where the parent stock came from.

08

In captivity

Rosy boas are a favorite pet snake because they stay small, are calm and easy to handle, and rarely bite. Keep one snake per enclosure; they are not social. A front-opening enclosure of about 36 × 18 × 18 inches suits most adults, and bigger is better. Short, regular handling sessions help a new snake settle.

  • Heat. A basking surface of about 85–90°F (29–32°C) with a cool end of about 75–80°F (24–27°C). Heat can go off at night, letting temperatures fall as low as about 60°F (16°C), and many keepers give a cooler winter rest.
  • Humidity and hides. Keep the enclosure mostly dry, below about 60% humidity, with a slightly damp hide on the cool side and several dry hides.
  • Substrate. Sand or a sandy soil mix at least 3–4 inches (8–10 cm) deep for burrowing; spot-clean daily.
  • Food. Whole prey such as appropriately sized mice, offered frozen-thawed. Juveniles typically eat every 5–7 days and adults every 10–14 days. Provide a small bowl of fresh water.
  • Lifespan. Well-kept rosy boas can live 30 years or more.

See a reptile vet if your boa has trouble shedding, wheezes or bubbles at the mouth, or loses weight while refusing food. More pet care guides

Keep reading

Sources

Data updated November 2026 · How we build these pages